public void StartCountdown(double seconds) { IObservable <long> obs = Extensions.ObservableExtensions.CountDown(seconds); _rTSSService.SetIsCaptureTimerActive(true); SetCaptureTimerValue(0); _disposableCountdown?.Dispose(); _disposableCountdown = obs.Subscribe(t => { SetCaptureTimerValue((int)t); _rTSSService.Refresh(); if (t == 0) { _rTSSService.SetIsCaptureTimerActive(false); } }); }